Magnetic core circuit



Dec. l0, 11963 J. c. MALLlNsoN l 3,114,133

MAGNETIC CORE CIRCUIT Filed Oct. l1, 1961 3,114,138 Patented Dec. 10.,- 1963 3,114,138 MAGNETIC CORE CIRCUIT John C. Mallinson, Harrisburg, Pa., assignor to AMP Incorporated, Harrisburg, Pa., a corporation of New Jersey Filed Oct. 11, 1961, Ser. No. 144,370

Claims. (Cl. 340-174) minor transmitting aperture of one core is connected via a coupling loop to a corresponding receiving aperture of the next core, yand so on. Information, in the form of magnetic flux stored in one core, is transmitted to the next core by a current generated in the coupling loop between them when the magnetic lux in the transmitting core is reversed by the application of an advance drive current.

Now one of the problems with such a circuit is the dithculty of obtaining MAD cores having the proper electromagnetic and other physical characteristics within suiiiciently close limits. Unless the lcores in a register are reasonably uniform and within close enough tolerances to the necessary values, the register will operate poorly, or not at all. This is particularly true Where the register is subjected to wide changes in temperature. The present invention to a large extent overcomes these problems.

In accordance with the present invention, in one specic embodiment thereof, a MADcore shift register, similar to the one described in the aforesaid patent application, is provided with additional toroidal magnetic cores inserted in the` respective coupling loops of the register. These additional cores, which are relatively inexpensive,

are carefully tailored to match certain of the characteristics of the MAD cores in the register. As a result MAD cores which otherwise could not be used in a satisfactory register, now become fully operative over a wide range of temperature. The toroidal cores are easily inserted in the circuitso that the cost of providing them is practically as low as the small price of the cores themselves. i

A better understanding of the invention together with a fuller appreciation of its many advantages will best be gained from a study of the following description given in connection with the single FIGURE of the accompanying drawing which is a schematic circuit of a shift register embodying features of the invention.

The shift register 1t) shown odd numbered (O) core 11 and an even numbered (E) core 12, each of which is made of magnetic ferrite material. Core 11 has a central aperture 13 which is coupled by an advance O drive winding 14. Similarly, core 12 has a central aperture 16 whichis coupled by an advance E winding 18. O core llrhas a minor output or transmitting aperture20 which is threaded by a cou-V pling loop 22, this loop also threading a minor input aperture 24`of E core 12. In the Ysame Way core 12 has an output aperture 26 which is threaded by a coupling pointed out in the following description.y

in the drawing includes an' provide an improved loop 28 whichk may be the output winding of the registerA or which may extend to yanother core (not shown).

Threading output apertures 20 and 26 is a prime Winding 30. The purpose of this winding is to apply threads a toroidal that a binary one can be aforesaid patent.

Now, it will be noted that coupling ,winding 22 also magnetic core 32. This auxiliary core is proportioned so that its number of ilux linkages (i.e. its

number of elastic ilux linkages of transmitting minor aper- `ture 20. Core 32 is also threaded by prime winding 30. Similarly, coupling Winding 28 is threaded by another toroidal core 34 itself Valso threaded by prime Winding 30.

Assume that the flux in the outer leg of O core 11 at aperture 20, which leg is encircled by coupling winding 22, is saturated with ilux in the downward or clockwise direction. This condition represents a binary zero stored in the core. Then on the occurrence of a current pulse on ADV O drive winding 14 (which current will be in a direction tending to set the ux in the core in the clockwise direction), the only flux switched in the outer leg of the core under winding 22 will be elastic ilux since this outer leg is already saturated with flux in the clockwise direction. This switching of elastic flux, however, generates a voltage which will tend to cause a noise current to flow in winding 22. Simultaneously, though, the advance current ilowing in winding 14 (which current is switching elastic flux in core 11) ilows in prime winding 30. Now, winding 38 threads auxiliarycore 32 in a direction such that the advance current switches remanent ux in the core in the clockwise direction. The switching of this remanent flux generates a voltage in coupling winding 22 which opposes and effectively cancels the elastic iiux voltage induced in the winding at core 11. In this arrangement, the switching of llux in auxiliary core 32 is not determined by current ilow in coupling winding 22. Here, therefore, the noise voltage can be almost exactly cancelled by the voltage from auxiliary core 32. Accordingly, virtually no noise current will tiow in winding Y22. This means, among other things, that the resistance of this winding can be reduced with the result more easily transmitted to core 12.

Y A short time after an advance current occurs on winding 14 and prime Winding 3), a prime current will be applied to thek latter. This current is in a reverse direction relative to an advance current. It therefore drives the flux in auxiliary core 32 into saturation in the counterclockwise direction. Thus this core is automatically conditioned for theV next transmission of a zero or a one, as described above. kAuxiliary core 34 functions in the same way as core 32, but on the occurrence of an advance Eto O drive current. I

The material from which cores 32 and 34 are made is not critical. They can be made of the same ferrite ma- In one lten bit n Y iic'ations in the embodiment described may occur to those be made without departing'from the spirit or scope of the'invention as set-forth.

skilled -in the` art and these can Y ture of one ycore and an 1I claim:

l. In a magnetic core information storage and transfer circuit: a 4iirst multi-aperture magnetic core having a minor output aperture, a second magnetic core, drive winding means linking said first core to saturate it with ux in a clear direction, means to set said iirst core with information, prime winding means threading said -rninor output aperture, said prime winding means being in series with at least a portion of said drive winding means, a coupling winding threading said output aperture and said second core, and an auxiliary magnetic core threaded by said coupling winding and said prime winding means, said auxiliary'core having a -flux content approximately equal to the elastic rtiux switched around the output aperture of said first core.

2. The circuit in claim l wherein said auxiliary core is proportioned to induce in said coupling winding a voltage substantially cancelling the elastic flux voltage induced therein by said first core. Y

3. A circuit of the character described comprising a plurality of multi-aperture magnetic cores, drive means threading said cores to drive them lrespectively to clear state, a coupling loop threading a minor output aperinput aperture of the next core to transfer information, and a small toroi'dal core threaded by said couplingy loop and said drive means, said toroidal core having a remanent flux content just slightly larger than the elastic flux switched around the minor output aperture of said one core. f

4. In an information shifting circuit of the character described, a plurality of multi-aperture magnetic cores, respective advance `drive means threading said cores in even and odd groups to advance information stored in the cores of one group to the next cores respectively in the other group and so on, means to set information into an initial core of the circuit, coupling loops each threading a respective minor output aperture of a core of one group and an input aperture of a core Yof the next core of the other group, a prime winding threading each said output minor aperture to reverse flux set locally therearound, said, prime Winding being in series with said advance drive means, and at least one magrnetic core linking one of said coupling loops and said prime winding.

5. The circuit in claim 4 wherein each of .said coupling loops threads the corresponding minor output aperture twice, threads an input `minor aperture of the next `core once, and threads the `corresponding toroidal core once, said toroidal core having a liux content approxi mately equal the elastic flux switched at said minor output aperture, said ltoroidal core setting before said next core sets.

No references cited. 

1. IN A MAGNETIC CORE INFORMATION STORAGE AND TRANSFER CIRCUIT: A FIRST MULTI-APERTURE MAGNETIC CORE HAVING A MINOR OUTPUT APERTURE, A SECOND MAGNETIC CORE, DRIVE WINDING MEANS LINKING SAID FIRST CORE TO SATURATE IT WITH FLUX IN A CLEAR DIRECTION, MEANS TO SET SAID FIRST CORE WITH INFORMATION, PRIME WINDING MEANS THREADING SAID MINOR OUTPUT APERTURE, SAID PRIME WINDING MEANS BEING IN SERIES WITH AT LEAST A PORTION OF SAID DRIVE WINDING MEANS, A COUPLING WINDING THREADING SAID OUTPUT APERTURE AND SAID SECOND CORE, AND AN AUXILIARY MAGNETIC CORE THREADED BY SAID COUPLING WINDING AND SAID PRIME WINDING MEANS, SAID AUXILIARY CORE HAVING A FLUX CONTENT APPROXIMATELY EQUAL TO THE ELASTIC FLUX SWITCHED AROUND THE OUTPUT APERTURE OF SAID FIRST CORE. 